B.13 Coronary Revascularization - CABG, PCI Flashcards
B.13 Coronary Revascularization - CABG, PCI
Define CABG
Coronary artery bypass grafting (or CABG) is a cardiac revascularization technique used to treat patients with significant, symptomatic stenosis of the coronary artery (or its branches). The stenosed segment is bypassed using an arterial (e.g., internal thoracic artery) or venous (e.g., great saphenous vein) autograft, re-establishing blood flow to the ischemic areas of the myocardium.
B.13 Coronary Revascularization - CABG, PCI
Indication for CABG
High-grade left main stem coronary artery stenosis
Significant stenosis (> 70%) of the proximal left anterior descending artery, with 2-vessel or 3-vessel disease
Symptomatic 2-vessel or 3-vessel disease
Disabling angina despite maximal medical therapy
Poor left ventricular function with myocardium that can return to function on revascularization
Postinfarct angina
B.13 Coronary Revascularization - CABG, PCI
Indications for emergency CABG
Non-ST segment elevation myocardial infarction with ongoing ischemia that is unresponsive to medical therapy/PCI
STEMI with inadequate response to all nonsurgical therapy
Significant ongoing ischemia, traumatic complications, or threatened occlusion in STEMI, after a failed PCI or previous CABG
B.13 Coronary Revascularization - CABG, PCI
CI CABG
There are no absolute contraindications for CABG.
Relative contraindications include:
- Asymptomatic patients with a low risk of myocardial infarction or death
- Comorbidities (e.g., COPD, pulmonary hypertension, systemic diseases)
- Advanced age
B.13 Coronary Revascularization - CABG, PCI
Basic Procedure
Thoracotomy via a midline sternotomy → cardiopulmonary bypass (heart-lung machine) → cardioplegic arrest of the heart → anastomosis of the bypass vessels distal to the coronary artery stenosis using autologous vessels
B.13 Coronary Revascularization - CABG, PCI
Types of Grafts
Arterial graft
Venous Graft
B.13 Coronary Revascularization - CABG, PCI
Arterial graft
Arterial graft - Arterial grafts have a better prognosis and patency rate than venous grafts.
Internal thoracic artery (internal mammary artery)
Good accessibility, close proximity to the heart
Left thoracic artery is suitable for bridging stenoses in the left anterior descending artery due to their close spatial proximity
B.13 Coronary Revascularization - CABG, PCI
Venous graft
Venous graft (aortocoronary saphenous vein bypass, or ACVB)
Great saphenous vein (first choice in vein bypass grafts because of good surgical access to the long, superficial leg vein with suitable vessel cross-section)
Small saphenous vein
B.13 Coronary Revascularization - CABG, PCI
Types of CABG
Traditional CABG - Vascular graft is sewn on by arresting the movements of the heart and redirecting the blood flow using a cardiopulmonary bypass (CPB) machine.
Off-pump coronary artery bypass (OPCAB) surgery - Grafting is done through a median sternotomy, with the heart beating (i.e., without CPB). It is usually preferred in patients with pulmonary, renal, or cerebrovascular comorbidities because CPB is known to cause a complex of systemic inflammatory responses and can lead to renal, pulmonary, neurologic, and coagulopathic complications, and even end organ dysfunction. However, graft occlusion and patency rates are known to be higher with OPCAB.
Minimally invasive direct, or totally endoscopic CABG - Approach to the coronary arteries is made through multiple small incisions made at the left intercostal spaces.
B.13 Coronary Revascularization - CABG, PCI
Complications
- Myocardial dysfunction
- Postpericardiotomy syndrome: autoimmune febrile pericarditis or pleuritis that may occur 1–6 weeks following cardiac surgery
- Postoperative cardiac tamponade with cardiogenic shock
- Bypass occlusion
- Arrhythmias
B.13 Coronary Revascularization - CABG, PCI
progonsis
Successful grafts typically last 8–15 years and provide an improved chance of survival (decreased 5-year mortality, especially in patients with triple vessel disease).
